The present invention relates to a device for extracting liquids contained therein and to an arrangement for filling that device with the liquids.
The device for extracting liquids of low to high viscosity, of the foregoing type is comprised of a cylindrical or tubular container having a head connected to a distributor for discharging liquid in form of drops, cord or spray, contained in the container from the same, and a non-mechanically movable piston inserted in the container and tight-sealed placed in the inner wall of the container and connected to the discharge device.
Devices of the foregoing type have been known and have been employed for packing tooth pastes and hair cremes in many structural forms. Filling of such containers with viscous liquids has been however problematic. It has been suggested to mount an output device and eventually a protective hood directly from the packing means manufacturer to the container whereas the piston and the base of the container must be loosely supplied thereafter because these structural components can be assembled on the container after the latter has been filled, and a multiple filling process with high expense as well as additional organization and stockage costs have resulted therefrom. Air must have been removed from the device for the proper function thereof. For this purpose, the container wall in the region of the initial position of the piston should be formed either lozenge-shaped or provided with grooves or webs for guiding air from the container. Thereby the sealing between the piston and the container wall must be effective, and the product discharge should be provided, upon the insertion of the piston, without permitting the products to be dried up and the piston to be blocked. The initial sealing of the piston in the insertion region in the conventional devices for high-viscous fluidic preparations is, however limited. With low-viscous liquids, high losses of the products contained in such devices occur, and the devices can malfunction due to suction of air into the container.
A further disadvantage of conventional devices resides in packing expenses, particularly with products for every day use. The discharge devices operated on the pressure/suction principle are also rather expensive. Also, specifically with pharmaceutical preparations, requirements to sterilization are not met in the known devices because during the insertion of the piston the sealing is not warranted. Finally it should be noted that it is impossible with conventional devices that the liquid can be removed automatically from the device as required with pharmaceutical products.